Seen a fly in your soup lately? Well, that's nothing compared with what you don't see in your strawberry yogurt or the sprinkles on your doughnut.

Crushed bugs. You've been eating them for years. You just didn't know it.

That's right. The "color added" ingredient in some red, pink and purple foods is carmine, the dried and crushed bodies of the female cochineal insect. The cactus-loving insect is used to color ice cream, yogurt, fruit juices and more.

"They're harvested in Mexico, processed in large plants. I've seen them," said Gary Reineccius, professor of food science at the University of Minnesota.

You may not have known, because they were hiding under the "color added" listing on the label, but you soon will. Starting in January, the Food and Drug Administration (FDA) is requiring manufacturers to switch from the "color added" label listing to "carmine" or "cochineal extract."

Consumers should know what's going into their food "to promote safe, healthy diets," said Michael Jacobson, executive director of the Center for Science in the Public Interest (CSPI) and part of the effort to require manufacturers to change their product labels.

Ingredients such as carmine have come under fire because they have been known to cause severe allergic reactions in some people. Those allergic reactions, along with a few subsequent lawsuits, have led some manufacturers to stop using carmine.

Other people with dietary restrictions, such as Jews and Muslims, may not consider some products kosher if these ingredients are included. But even those without restrictions might be a little squeamish if they knew just what was going into some of their food. The CSPI wants the FDA to go even further, labeling carmine as insects on packaging. After all, few people recognize carmine or cochineal as something that comes from insects, and even fewer would be curious enough to look it up online or in a dictionary to find out exactly what they're eating.

People would be disgusted if they knew crushed bugs were in their food, Jacobson said. "We urge the FDA to at least indicate these ingredients are of insect origins, but the industry opposes that because nobody would buy the product."

Using ingredients like carmine can be deceptive, according to Jacobson, because the color it gives to products makes it appear as though there is real fruit included when there often isn't.

Some other surprising food ingredients with an ick factor include:

• Shellac: The secretions from the lac beetle found in India and Thailand are used to give confections such as Skittles and candy sprinkles a shiny coating.

"Nothing synthetic does this as well," Reineccius said, adding that, yes, it's the same shellac that's used to finish wood. Jacobson said it can also be used on fruits and vegetables to seal them.

• Rennet: An enzyme taken from veal calves at the time of slaughter is added to milk to make cheese. At some point in ancient history, someone put milk in a bag made of a calf's stomach and discovered that it curdled, and cheese was born. A non-animal version is microbial enzyme. It sounds better when it's listed as "vegetable rennet" on cheese labels.

• Honey: The sweetener that's been used for thousands of years is basically regurgitated pollen. Some prefer it because it's completely natural, but many might just want to forget where it's been.

• Castoreum is bizarre, said Reineccius. It's a secretion from the anal glands of beavers, used mostly in perfumes and sometimes to enhance raspberry flavor in candies and fillings. How did it make the jump from beavers to perfume?

"Probably by accident," he said. "More than likely somebody was hunting and, guess what, they used all of the animal. They said, 'That's an interesting aroma, and how can we use that?'"

If you'd never imagined ingredients like these being used in your foods, you'd be even more surprised by what Jacobson says your food would look like without these products: Not different at all.

"They'd use some other coloring," he said. "They need to give it some color, and it just gives it what they consider the right color."